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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Deep geologic repository progress—2025 Update
Editor's note: This article has was originally published in November 2023. It has been updated with new information as of June 2025.
Outside my office, there is a display case filled with rock samples from all over the world. It contains a disk of translucent, orange salt from the Waste Isolation Pilot Plant near Carlsbad, N.M.; a core of white-and-bronze gneiss from the site of the future deep geologic repository in Eurajoki, Finland; several angular chunks of fine-grained, gray claystone from the underground research laboratory at Bure, France; and a piece of coarse-grained granite from the underground research tunnel in Daejeon, South Korea.
A. V. Zhirkin, V. P. Budaev, A. V. Dedov, A. A. Glebova, A. O. Goltsev, A. T. Komov, B. V. Kuteev
Fusion Science and Technology | Volume 79 | Number 6 | August 2023 | Pages 703-722
Research Article | doi.org/10.1080/15361055.2023.2178869
Articles are hosted by Taylor and Francis Online.
The modern challenges of nuclear energy are the replenishment of dwindling reserves of nuclear fuel and the development of a closed nuclear fuel cycle while complying with strict radiation safety requirements. A fusion neutron source has unique capabilities to solve these problems. The preliminary results of a neutronic analysis of the FNS-C fusion-fission hybrid neutron source with a thorium-uranium aqueous blanket by the Monte Carlo method computer simulation, using the MCNP-4 code with the ENDF/B-VII cross-section library, gives satisfactory results for the study of the possibility of creating a compact source of fusion neutrons based on a small spherical tokamak for commercial use.
The obtained results show that the FNS-C hybrid blanket generates enough tritium to fully ensure the uninterrupted operation of the FNS-C throughout the year. The reproduction coefficient of 233U is 1.027 at a consumption of 1304 kg/year of the fissile material in the aqueous blanket containing 232Th enriched to 1.47% 233U. The FNS-C is operated with an effective neutron multiplication factor keff ~ 0.99 with reactivity ρ = –0.006249 in the presence of delayed neutrons, which corresponds to the safest state of the core of thermal neutron fission reactors. The thermal power of the FNS-C at keff ~ 0.99 is ~3 GW, which is comparable to the thermal power of fission reactors. This indicates the potential possibility of creating a safe thorium-uranium breeder power reactor based on a fusion neutron source. The results of the study were obtained for the simplified approximate geometrical FNS-C model. To confirm the preliminary results, it is necessary to develop a more accurate calculation model of the FNS-C machine.